The present invention relates to semiconductor devices and pertains particularly to an opto-coupler and method of making same.
Opto-coupler devices comprising a light emitting diode and associated light sensing IC circuit are useful as high-speed miniature switching devices in minature electronic circuits. Such devices, however, because of their size are difficult to assemble.
Conventional assembly and packaging of opto-coupler devices require the use of two lead frames. The light emitting diode is mounted on one of these lead frames and the sensor integrated circuit is mounted on the other lead frame. The lead frame with the LED is then aligned to the sensor portion of the integrated circuit and the two LED frame secured together such as by welding or by encasement in a plastic body. With this construction and approach, however, the vertical separation of the light emitting diode sub-assembly and the alignment thereof is difficult to achieve causing poor final test yields and a high percentage of rejects.
Accordingly, it is desirable that an improved opto-coupler construction and metnod of making same be devised.